There are four main types of aircraft engines: the conventional reciprocating engine, the turbo charged/fuel injected reciprocating engine, the prop jet, and the turbo jet engine. There are also two lesser used types of engines: the ram jet and the pulse jet. There are, of course, several variations of each type. The said four main types of engines have an increasing number of internal moving parts, causing increasing complexity, cost, and requiring increasingly longer durations of time for routine inspections, and parts replacement. The many internal moving parts also increase the chances of malfunction, caused by wear of said parts and from foreign object damage. The said lesser two used types of engines have their own set of draw backs. The ram jet suffers from horrendous fuel consumption at low speeds and requires an auxiliary motor to bring its craft velocity up to a minimum engine operational speed. The pulse jet suffers from excessive noise, vibration, and the valve system is highly unreliable, therfore unsafe for manned craft. The pulse jet also suffers from a decrease of thrust as its craft velocity increases, there by limiting the engines maximum operational speeds. The commonly used fuels are of a slow energy output and high pollution output that decreases the overall effectiveness of all the said engines.
There are four main types of general power plants: the conventional reciprocating engine, the turbo charged/fuel injected engine, the diesel engine, the turbo charged/fuel injected diesel engine, and the lesser used rotary and two cycle engines. There are of course several variations of each engine type. The said four main types of power plants have an increasing number of interacting moving parts, causing increasing complexity, cost, and requiring increasingly longer durations of time for routine inspection and parts replacement. The many internal moving parts also increases the chances of malfunction, commonly caused by wear of said parts and from foriegn object damage. Since potential work energies developed by the afore mentioned power plants is rotational about the drive shaft axies, all the said power plants must be within close proximity of their intended work elements else torrsional stresses will cause rapid fatigue of energy transfer elements. The commonly used fuels are of a low energy and high pollution output that decreases the overall effectiveness of all the afore to said engines.